Einstein was right, neutrino researchers admit

A team of scientists who last year suggested neutrinos could travel faster than light conceded Friday that Einstein was right and the sub-atomic particles are — like everything else — bound by the universe’s speed limit.

Researchers working at the European Centre for Nuclear Research (CERN) caused a storm when they published experimental results showing the particles could out-pace light by some six kilometres (3.7 miles) per second.

The findings threatened to upend modern physics and smash a hole in Albert Einstein’s 1905 theory of special relativity, which described the velocity of light as the maximum speed in the cosmos.

The neutrinos were timed on the journey from CERN’s giant underground lab near Geneva to the Gran Sasso Laboratory in Italy, after travelling 732 kilometres (454 miles) through the Earth’s crust.

To do the trip, the neutrinos should have taken 0.0024 seconds. Instead, the particles were recorded as hitting the detectors in Italy 0.00000006 seconds sooner than expected, the preliminary experiment had shown.

But on Friday the OPERA team told the International Conference on Neutrino Physics and Astrophysics, being held in Japan’s ancient capital of Kyoto, that the earlier results were wrong.

“The previous data taken up to 2011 with the neutrino beam from CERN to Gran Sasso were revised taking into account understood instrumental effects,” the team said.

“A coherent picture has emerged with both previous and new data pointing to a neutrino velocity consistent with the speed of light.”

The initial findings had been greeted with a combination of excitement and scepticism, even from those involved in the experiment, who urged other physicists to carry out their own checks to corroborate or refute what had been seen.

As part of this verification, an experiment called ICARUS at the Gran Sasso Laboratory took a separate look at the flight of seven neutrinos that had also been recorded by the OPERA team.

Carlo Rubbia, a Nobel winner and spokesperson for the ICARUS project announced the neutrinos had kept within the universal speed limit.